Power operated can opener with variable automatic shut-off



Aug. 15, 1961 R. J. SCOTT ET AL 2,995,817

POWER OPERATED CAN OPENER WITH VARIABLE AUTOMATIC SHUT-OFF Filed Feb.15, 1960 3 Sheets-Sheet 1 1? llllllllllllllllllllIl-illlllllllll Robe/fJ Scoff W/Y/lC fl? A Chappe/l Joseph L. Gran? William J. LandryINVENTORS.

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Aug. 15, 1961 R. J. SCOTT ET AL POWER OPERATED CAN OPENER WITH VARIABLEAUTOMATIC SHUT-OF F Filed Feb. 15, 1960 3 SheetsSheet 2 Wi/l/am ,4.C/mppefl Jaseph 1. 6/0/77 Wf/fiam J. Landr INVENTOR ATTOR/VFX 3Sheets-Sheet 3 A TTORNE K 7 m H 3 3 e m r w wflm p 2 wmmnm b m 9 3 CGM HV ll 6 mid m in M w /U JW JV Aw m m KAAAAAARMAQAAAAAR Wm P ow w ww Aug.15, 196 R. J. SCOTT ETAL POWER OPERATED CAN OPENER WITH VARIABLEAUTOMATIC SHUT-OFF Filed Feb. 15, 1950 2,995,817 POWER OPERATED CANOPENER WITH VARIABLE AUTOMATIC SHUT-OFF Robert J. Scott, Blue Springs,William A. Chappell and Joseph L. Grant, Raytown, and William J. Landry,Blue Springs, Mo., assignors to John C. Hockery, Kansas City, Mo.,trustee for Henry J. Talge and Foster L. Talge Filed Feb. 15, 1960, Ser.No. 8,699 10 Claims. (Cl. 304) This invention relates generally toelectricallly powered can openers and refers more particularly toimprovements therein with respect to providing a variable shutoffoperable to positively and automatically control the length of thecutting operation so as to adapt the can opener to timed operation withvarious sizes of cans.

One of the objects of the present invention 1s to provide improvementsin electrically powered can openers of the lever type generallydisclosed in the Aberer et 21. Patent 2,902,757, issued September 8,1959, which improvements are directed to the incorporation in such a canopener of means for relating the period of operation of the motor to thesize of the can being opened. It is a special feature of the presentinvention that the automatic control of the operational period isachieved while still retaining all of the advantages of the manual powercontrol resulting from the arrangement described in the aforementionedpatent.

Another object of the present invention is to provide an automaticvariable shut-off for power operated can openers of the characterdescribed in which, through the unique relationship of the functioningparts, the electrical system is of extreme simplicity, requiring but asingle switch.

A further object of the invention is to provide a variable selectivecontrol mechanism for power operated can openers which is so arrangedthat the control can be overridden by the operator to increase theperiod of cutting if such proves necessary or desirable.

Still another object of the invention is to provide a power operated canopener with a variable automatic shut-ofi which is capable of adjustmentto the selected period of operation with ease and facility, and withoutinterfering with or requiring adjustment of the functional can cuttingand feeding elements of the unit.

A further object of the invention is to provide a simple and reliablemechanism for accomplishing the foregoing results. The variable shut-otfelements and operating mechanism are so arranged that they can beincorporated into certain presently known can openers without requiringany basic redesign or retooling.

Still another object of the invention is to provide a variable shut-01fcontrol for power operated can openers of the type described in whichthe can opener is capable of manual control in the event of failure ormalfunction of the automatic control mechanism.

Other and further objects of the invention together with the features ofnovelty appurtenant thereto will appear in the course of the followingdescription.

In the accompanying drawings which are to be read in conjunction withthe specification and in which like reference numerals indicate likeparts in the various views:

FIG. 1 is a front elevation of a typical power operated can openerembodying the features of the invention;

FIG. 2 is a rear elevation of the can opener, slightly enlarged, withthe casing removed and with parts of the drive worm and gear broken awayfor purposes of illustration;

FIG. 3 is a top plan view of the can opener, the outer nited StatesPatent l 2,995,817 Patented Aug. 15, 1961 casing being again absent andpart of the base being broken away;

FIG. 4 is a fragmentary sectional view taken generally along the line 44of FIG. 3 in the direction of the arrows;

FIG. 5 is a fragmentary front elevation illustrating the relationshipbetween the hand lever and cutter wheel plate and between the latter andthe feed wheel, at the moment of firm engagement of the cutter wheelwith the can lid at the inception of the operating cycle;

FIG. 6 is a fragmentary rear View showing the relationship between thethrust element and shut-off control arm when the hand lever is in theposition illustrated in FIG. 5;

FIG. 7 is a fragmentary sectional view taken along the line 77 of FIG. 6in the direction of the arrows;

FIG. 8 is a view similar to FIG. 5, but illustrating the relationship ofthe hand lever, cutter wheel plate and feed wheel following initialdisplacement of the plate and shifting of the shut-oil control arm tomotor starting position;

FIG. 9 is a sectional view similar to FIG. 7 illustrating therelationship of the thrust element and shut-off control arm when theopener is in the condition illustrated in FIG. 8;

FIG. 10 is a view similar to FIGS. 5 and 8, but illustrating the platein its fully depressed condition and just prior to piercing of the canlid;

FIG. 11 is a view similar to FIGS. 7 and 9, but illustrating theposition and relationship of the thrust element and shut-0E control armwhen the can opener is in the condition illustrated in FIG. 10; and

FIG. 12 is a fragmentary detail taken generally along the line 12-12 ofFIG. 3 in the direction of the arrows.

Referring now to the drawings, the invention will be described inconnection with an electrically powered can opener having theconstruction disclosed in the aforementioned Patent 2,902,757. All ofthe details of the basic can opener structure and operating mechanismare described in full in that patent and will not be repeated hereexcept as necessary to clarify the relationship with the improvementsherein set forth.

Generally speaking, the can opener unit includes a base 10 from theforward edge of which rises an essentially vertical face plate andsupport structure 11 which serves the purpose of supporting at its upperend the operating mechanism of the can opener. A hollow, generallythree-sided casing 12 houses the various operating parts of the driveand control mechanism. For reasons of simplicity in description thishousing has been shown only in FIGS. 1, 5, 8 and 10, being absent fromthe remaining figures.

As may be determined in greater detail from the forementioned patent,the basic operating mechanism of the can opener unit includes a rotaryfeed wheel 13 with which cooperates a cutter wheel 14. The feed wheel issecured to a drive shaft 15 which is supported for rotation about afixed axis extending horizontally from the face plate 11, beingjournaled with respect to the latter in a boss 11a which projects fromthe rear side of the face plate (see FIG. 3). While the feed wheel ismounted for rotation about a fixed axis, the cutter wheel is carried bya plate structure 16 which is operable in response to manipulation of ahand lever 17 to separate the cutter wheel from the feed wheel to permitinsertion of a can rim therebetween, and to again bring the two togetherso as to pierce the can lid. The position of the hand lever 17 and platestructure illustrated in the solid lines in FIG. 1 is that which obtainsafter the lid has been pierced. The broken line position illustrates thepositions of the hand lever, plate and cutter wheel prior to institutingoperation.

As again may be seen from the Aberer et al. patent, the movement of theplate 16 between the solid and broken lines p sitions is in response tothe swinging of the hand lever 17 between its solid and broken linepositions. The plate is coupled with the hand lever through an eccentriccam arrangement, one element of which is seen at 18. The cam is keyed tothe hand lever 17 and acts as a crank arm for moving the main body ofthe plate about the feed wheel axis between the two positions shown.

The left-hand end of the plate 16 moves generally linearly in ahorizontal direction toward and away from the feed wheel axis inresponse to manipulation of the hand lever between the positions shown.This is due to the fact that the plate 16 is provided with a rearwardlyextending arm 19 which extends through a large aperture A in the faceplate 11. (See FIGS. 6 md 7.) The aperture A is provided with ahorizontal upper edge 11b and lower edge 11c. Normally the upper surfaceof arm 19 is maintained in sliding engagement with edge 11b by a tensionspring 20 which is connected at one end with a second lug 16a extendingrearwardly from plate 16 through the aperture A, and at the other endwith a fixed lug 21 extending rearwardly from the face plate 11 abovethe aperture. The action of the cam coupling between hand lever 17 andplate 16 causes the arm 19 to slide horizontally along edge 11b, themaximum displacement to the right (as viewed in FIG. 2) occurring withthe hand lever in a position midway between the solid and broken linepositions of FIG. 1. The midway position is illustrated in FIGS. and 6.

As also disclosed in the aforementioned patent, plate structure 16 andhand lever 17, when in the solid line positions, are coup-led to operateas a unit capable of limited rotary displacement in a clockwisedirection (FIG. 2) about the axis of the feed wheel. In other words, bypressing downwardly on the hand lever 17, both the hand lever and plate16 are caused to rotate about the shaft 15 a limited distance. Rotationof the plate relative the shaft when the hand lever is separated fromthe plate can also be occasioned, this being accomplished by inserting acan lid between the cutter wheel and feed wheel and applying pressure tothe hand lever, as is shown in FIGS. 5, 8 and 10, the can lid serving totransmit the thrust applied to the handle and transform it into a momenttending to turn the plate about the shaft 15. More will be said of thislater. The left-hand end of plate structure 16 is, of course, biasedtoward and normally maintained in the position illustrated in solidlines in FIG. 1 by the tension spring 20, as previously described. Theaperture A is large enough to accommodate the necessary movement of thelug 16a, and thus plate structure 16, about the shaft 15 upon depressionof the hand lever.

The driving power for the can opener is supplied through the medium ofelectric motor 22. The motor is vertically oriented on the base andterminates in a drive shaft 23 provided with a worm 23a. The worm drivinly engages the teeth of a gear 24 secured to the horizontal feed wheelshaft 15. Preferably, the gear 24 is constructed of nylon or other toughplastic. It is secured to shaft by means of a flanged collar 25 pressfitted onto the end of the shaft, one face of the gear body beingsecured to the collar by screws 26.

The electrical control for the motor comprises a snap acting switch Swhich is mounted by suitable supporting structure on an insulating base27 to the rear of the face plate 11 and below the aperture A. 'As bestseen in FIG. 12, switch S includes the fixed contact 23 and the normallyopen but movable contact 29. The switch may be of the conventionalover-center type illustrated, having the operating arm 30 terminating inthe depressor portion 300 at its free end. As will be evident, theportion 30a is positioned in the downward path of the lug 16a so thatthe contacts will be closed when the latter lug is displaced downwardlyby limited movement of the plate 16 from its normal position against theforce of the spring 20. It will be understood that the switch S isinterposed in series in the motor electrical circuit, the leads 31a and31b being connected with the respective contacts 28 and 29. The switchoperating arm 30 is continually biased upwardly so that when downwardpressure is removed from the portion 30a the arm will return to itsoriginal position and cause contact 29 to disengage from the fixedcontact and cause the motor to stop. The arm is so arranged with themovable contact that the initial increment of downward movement of thearm causes closing of the contacts. By the same token, reopening of thecontacts does not occur until the arm is near the upper end of itsmovement.

It may help in obtaining a clear understanding of the invention torepeat that with the exception of the specific arm 19 herein shown, allof the features of the can opener described thus far are disclosed inthe Aberer et al. patent referred to above, and that such details ofconstruction as are not herein specifically set forth can be gained fromthat patent. Thus far we have set forth a manually controlled poweroperated can opener in which the operation of the motor is maderesponsive solely to the application and release of external pressure tothe hand lever by an individual, the period of operation depending onhow long the pressure is kept on the hand lever. The present inventionis designed to supplement this arrangement with novel means forautomatically maintaining the motor energized following starting, eventhough manual pressure is removed from the hand lever 17, and to stopthe motor after a predetermined interval has passed, without changingthe basic nature of the can opener mechanism.

One of the principal elements of our present invention comprises apivotal switch control member 32 which in the illustrated embodiment isin the form of an elongate arm pivoted at one end by a screw 33 formovement about an axis parallel with the feed wheel shaft 15. The member32 is mounted behind the face plate 11, the pivot screw 33 beingreceived and retained in a boss 44 extending rearwardly from and securedto the face plate. As viewed from above (FIG. 3) the control member isprovided with a rearwardly bent portion 32a which continues in anextension 32b disposed fairly close to the plane of the forward face ofthe gear 24. A reverse bend 32c is provided at the outer end ofextension 3212 and continues into a further extension 32d from which thearm turns downwardly to provide the vertical leg 32c which terminates ina horizontal shoe portion 32 more of which will be said later.

It will be observed that secured to the intermediate portion 32b of thecontrol member is a leaf spring 34 which terminates in a free enddisposed closely adjacent the forward face of gear 24. The end of spring34 is equipped with a stylus 35 which is resiliently pressed by thespring into contact with the face of the gear.

As may best be seen in FIG. 4, the forward face of the gear 24 isprovided with a groove 24a spiraling outwardly about the gear axis. Theinner end of the spiral groove terminates at the outer margin of acircular face portion 24b in which the stylus is free to ride withoutcausing any displacement of the control member 32,. So long as thestylus remains in the position shown in FIG. 4, the groove will have noinfluence on the control arm. However, if the arm 32 is pivoteddownwardly (for example to the broken line position of FIG. 2) thestylus will be moved downwardly and transversely across the groove andcome to rest in the groove at a point determined by the extent ofpivotal displacement of the control member. The resilient character ofthe leaf spring 34- permits the stylus to ride in and out of the groovevalleys as it moves transversely across the face of the gear. Theorientation of the groove 24a in the gear is such that when the motor isstarted the surfaces of the groove will progressively drive the stylusback toward the gear center, the stylus carrying With it the controlmember 32.

The normal position for the control member 32 is that illustrated in thesolid lines of FIG. 2. This corresponds to the position of the stylusillustrated in solid lines in FIG. 4. No matter to what extent thecontrol member may have been displaced during any phase of theoperation, it always returns to this normal position in response torotation of the gear 24, which is always in the same direction.

The downward displacement of the control member during operation isaccomplished under the influence of a thrust member 36 which isconnected with and depends from the outer end of arm 19. Referring toFIGS. 2 and 7, it will be observed that the thrust member 36 ispivotally connected With the end of a headed pin 37. The pin extendsthrough a suitable aperture in the arm and is retained against removalby a nut 38 which is connected With the threaded end of the pin.Surrounding the pin between its head and arm 19 are the coils 39 of atorsion spring having one end 39a in bearing engagement with the thrustmember, and the other end 39!) retained by the arm 19. Obviously, spring39 exerts a moment upon thrust member 36 tending to maintain it inyielding sidewise engagement with the control member 32. The thrustmember is provided with a rounded shoulder 36a which is normallydisposed above and which is operable to engage, under certain conditionsof operation, the upper surface of portion 32g of the control member,thereby to apply downward thrust upon the control member responsive todownward movement of the arm 19. However, it will be noted that ifdownward movement of the control member is restricted or interferedwith, the shoulder 36a can ride outwardly until it clears the edge ofsurface 32g of the control member, thus permitting the arm 19 to movedownwardly independently of the control member.

The control member 32 is provided with a notch or recess 32h in itsupper surface which is so located and has such a depth that when theplate structure 16 is in its normal can cutting position vis-a-vis thehand lever 17 (the solid line position of FIG. 1) the shoulder 36a ofthe thrust member is capable of moving up and down in response tomovement of the plate structure without contacting the control member.The shoulder 36a only engages the portion 32g of the control member whenthe plate is in a position corresponding to a position of the hand levermidway between the solid line and broken line positions of FIG. 1.

As may best be seen in FIGS. 3 and 12, control member 32 is providedwith a laterally extending tongue 40 which overlies and is capable ofdepressing the depressor 30a of the switch operating member 30 upondownward pivoting of the control member. In the normal position of thecontrol member the tongue 40 is just above the depressor, leaving thecontacts of the switch open. Initial downward movement of the tongue 40results in closing of the contacts through the medium of the switchoperating member 30.

The extent of permissible movement of the control member 32 downwardlyfrom its normal position is governed by a cam body 41 which ispositioned near the base of the unit and in the path of the shoe portion32 of the control member. The cam surface 41a is contoured substantiallyas shown. The cam body 41 is rotatable, being secured to a shaft 42which is journaled in a bearing boss 43 which may conveniently be castas an integral part of the face plate 11. A friction imposing take-upspring 45 is interposed between a retainer flange 42a and theconfronting end of the boss 43. The shaft 42 extends through the faceplate and has secured to its outside end a control knob 46 fitted withan indexing pointer 46a. The pointer cooperates with a scale 47 markedoff in increments of average can diameters and also including an areamarked manual.

The configuration of the cam surface 41a in the illustrated embodimentis such that it provides for progressive limitation of the downwarddisplacement of the control member as the cam body is turned clockwiseon its shaft 42 as viewed in FIG. 2. Thus the solid line position of thecam shown in FIG. 2 corresponds to the maximum permissible downwarddisplacement of the control member; the intermediate position (in brokenlines) at 41 represents essentially a permissible motion ofapproximately one-half the full range; and the position 41" (also inbroken lines) represents a position for the cam which prevents anydownward movement of the control arm. To assist in understanding therelationship between the index or scale on the exterior of the faceplate with the cam position, the pointer 46a is shown in FIG. 1 in thecorresponding broken line positions it assumes, these being identifiedas 46a and 46m" respectively. It will be observed that in theillustrated embodiment the range of rotation of the cam 41 is through anarc of the lowermost position being indexed by an extension 41b on thecam body engaging an abutment 11d on the rear of the face plate and theuppermost by the engagement of the cam surface 41a with such abutment.

The operation of the invention will perhaps be best understood byexplaining it in connection with the opening of a large diameter can.

In this case, the first action taken is to manipulate knob 46 to indexthe pointer in the large area of the scale 47 which results in the camposition illustrated in solid lines in FIG. 2, as earlier explained. Thehand lever 17 is then swung upwardly and outwardly to the broken lineposition of FIG. 1, which, as previously noted, separates the cutterWheel 14 from the feed wheel 13 and permits insertion therebetween ofthe rim and adjacent lid portion of a can. While holding the can in thisposition the hand lever is moved back toward its original position untilthe lid is engaged firmly between the cutter wheel and feed Wheel. Thisis the condition of the assembly illustrated in FIGS. 5, 6 and 7. Inthese and succeeding figures the can body is identified by referencenumeral 50 and the lid by 5-1.

Due to the previously described eccentric coupling between the handlever 17 and plate structure 16, the plate structure 16 is, in the FIG.5 condition, so located that the shoulder 36a of thrust member 36 nowoverlies the upper surface 32g of the control member 32. In other words,the plate structure has shifted slightly to the right of its FIG. 2position. The relationship now existing between the thrust member andcontrol member is clearly shown in FIGS. 6 and 7.

To produce piercing of the can lid and start the operation of the motoradditional counter-clockwise pressure is applied to the hand lever,sufficient pressure being applied to overcome the resistance of theplate spring 20 so that the plate structure is pivoted along with thehand lever, causing the arm 19 to disengage from. edge 11b and pushingthe thrust member 36 downwardly. The tension in spring 29 is ordinarilyinsufficient to hold the plate structure against the turning momentimposed thereon by the engagement of the cutter wheel 14 with the canlid.

The downward movement of the thrust member 36 is accompanied by downwardpivoting of the control member 32 because of the engagement of theshoulder 36a therewith, and the control member will be moved downwardlyuntil it is stopped by engagement of the shoe 32 with the cam surface41a of cam body 41. The motion of the control member results in downwarddisplacement of the stylus 35 across the spiral groove 24a and thesetting of the stylus in a position (35 in FIG. 4) near the rim of thegear. At the same time the switch lug 16a on the plate structure engagesand depresses the switch operating arm 30 to close contacts 28 and 2.9and start the motor.

As the motor starts the operator continues to hold the closing orpiercing pressure on the hand lever 17 and the combination of therotation of the feed wheel and hand applied pressure causes the cutterwheel to pierce the can lid. As the cutter wheel moves through the lid,the hand lever approaches and comes into its aligned or closed positionrelative to the plate structure. Ordinarily the tension spring 20 will,once the lid is pierced, serve to again raise the end of the platestructure 16 back to the FIG. 7 position. In other words, once piercingof the can has taken place and the hand lever has reached the solid lineposition of FIG. 1, the pressure on the hand lever can be removed and,as will be seen, the unit will operate automatically from this point on.

The release of the hand lever, and return of the plate structure 16 toits upper position as limited by arm 19, removes from the switch arm 30the depressing pressure of lug 16a. However, the tongue 40 on thecontrol member 32 now takes over, holding the switch closed until thecontrol member again returns to its normal position. It is thus obviousthat so long as the control member 32 remains below its normal position,the motor will continue to run and cause the feed wheel 13 to feed thecan into the cutter wheel 14.

The spiral groove 24a in the face of gear 24 serves the function ofreturning the control member 32 to the normal position in timed relationwith the number of revolutions of the feed wheel succeeding theinitiation of operation of the motor. As the gear rotates, the stylus 35is displaced back toward the center of the gear, lifting along with itthe control member to which it is attached. During this time the tongue40 continues to hold switch closed and the motor continues to operate.Just as the control member 32 reaches its normal position, the contact29 of the switch snaps open and the motor stops without requiring anyaction by the operator.

It will be evident that the time interval of operation of the motor canbe varied by simply changing the amount of downward displacementpermitted the control member 32. This function is, as previously noted,served by cam body 41 which can be positioned to limit the travel of thecontrol member to any desired degree. The shorter the travel, theshorter the time interval of operation of the motor and the smaller thecan that will be completely opened.

It may develop in certain cans that piercing of the lid will not takeplace until the plate structure 16 has reached a position where arm 19engages the lower edge 110 of aperture A (FIGS. and 11) and isimmobilized against further turning with the hand lever. Since thecontrol member 32 is intercepted by cam 41 before this occurs, thethrust member 36 merely rides outwardly on and is disengaged from itsthrust connection with the control member so that the plate structurecan continue to move independently of the control member. When the platestructure again lifts, the torsion spring 39 causes the shoulder 36a toreassume its position above surface 32;; of the control member. It willbe understood that the strength of the torsion spring is sufficient tohold the shoulder 36a inwardly on surface 32g so long as the onlyresistance encountered in movement of the control member is that imposedby the resistance to movement of the stylus in and out of the groovevalleys.

By turning the cam body 41 to prevent movement of the control member 32from its normal position (see 41" in FIG. 2) the unit becomes subject tomanual control only. The thrust member 36 moves without causing anydisplacement of control member 32 and the only control over the switchis that provided by the plate lug 16a.

It will further be evident that should it at any time be desired tooverride the automatic shut-01f herein provided, this is accomplishedsimply by pressing downwardly on the hand lever 17, causing platestructure 16 to turn therewith and to depress the switch operating arm30 by the lug 16a.

. From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. In a power operated can opener, the combination of a rotatable feedwheel, an electric motor drivingly conneoted with said feed wheel,switch means connected with said motor and having a motor energizingcondition and a motor deenergizing condition, a cutter member, a carrierfor said cutter member, said carrier supported for movement of thecutter member relative to the feed wheel into and out of can cuttingrelationship with the feed wheel, a movable switch control memberoperably connected with said switch means whereby said control memberhas a first position relative to said switch means wherein the switchmeans is in the motor deenergizing condition and a second positionwherein the switch means is held thereby in the motor energizingcondition, thrust means connected with said carrier and cooperating withsaid control member whereby to shift said control mem her to said secondposition in response to movement of said carrier and can cutter memberinto said can cutting relationship, and spiral camming means connectedwith and driven by said motor and having engagement with said controlmember, said camming means causing said control member to return to saidfirst position in response to a preselected number of revolutions ofsaid feed wheel whereby to cause said motor to stop upon the completionof said preselected number of revolutions.

2. In a power operated can opener, the combination of a rotatable feedwheel, an electric motor drivingly connected with said feed wheel,switch means connected with said motor for starting and stopping same,said switch means including a switch operating member resiliently biasedtoward and normally disposed in the stop condition, manually depressiblemeans for engaging said operating member to displace same and start saidmotor, a body coupled with said feed wheel for rotation therewith, saidbody having a spiral camming groove disposed in a plane substantiallynormal to the axis of rotation of said body and the groove spiralingabout the axis of ro tation, a movable control member having a stylusbiased toward said groove, said control member displaceable in a path toplace said stylus at varying distances from one end of the groove, thegroove operating to return said stylus and control member toward one endof the groove upon rotation of the feed wheel, thrust means actuatedresponsive to depression of said manually operable means and operable toengage and displace said control member in a direction away from saidone end of said groove, and means connected with said control member andoperable to engage and prevent return of said switch operating member toits normal position until the stylus has moved a selected distance backtoward said one end of said groove in response to rotation of said body.

3. The combination as in claim 2. including adjustable stop meanspositioned in the path of said control member and operable to controlthe extent of displacement of said control member responsive todepression of said manually operable means.

4. The combination as in claim 3 wherein said thrust means includesmechanism operable to permit disengagement of said thrust means fromsaid control member and further depression of said manually operablemeans in the event said control member is immobilized.

5. The combination as in claim 3 wherein said stop means comprises arotatably adjustable cam body having an eccentric cam sunface whoseposition relative the control member is changed rmponsive to rotation ofthe cam body.

6. The combination as in claim 5 including means for visually indexingthe cam body in a selected position.

7. In a power operated can opener of the type having an electric motor,a rotary feed wheel coupled with said motor and driven thereby, a cutterwheel, a shiftable carrier for said cutter wheel supported for movementof the cutter wheel toward and away from the feed wheel whereby topermit insertion of a can top therebetween, means for shifting saidcarrier, and further means mounting said carrier for limited movement inresponse to can piercing pressure when applied to said last named meansand prior to piercing of said can, the combination therewith ofelectrical switch means connected with said motor for starting andstopping same, said switch means including a switch operating memberresiliently biased toward the stopped condition, a movable switchcontrol member associated with said carrier member and having a normalposition out of engagement with said operating member, said controlmember movable in a path to engage said operating member and cause sameto start said motor in response to said limited movement of saidcarrier, and means driven by said motor and operatively associated withsaid control member to return same to said normal position in responseto a preselected number of revolutions of said feed wheel whereby todisengage from said operating member and cause said motor to stop.

8. In a power operated can opener as in claim 7, the combination whereinmeans are provided for variably controlling the displacement of saidcontrol member, said last named means comprising an adjustable stopdisposed in the path of said control member.

9. In a power operated can opener as in claim 7, the combination whereinsaid last named means includes a spiral camming surface connected withsaid feed wheel and rotatable therewith.

10. In a power operated can opener as in claim 7, the combination whichincludes means on said carrier member operable to engage said switchoperating member independently of movement of said control member uponsaid limited movement of said carrier member in one direction.

References Cited in the file of this patent UNITED STATES PATENTS2,755,548 Fleming July 24, 1956 2,893,116 Aberer July 7, 1959 2,902,757Aberer et al. Sept. 8, 1959

